P0734 Code: Gear 4 Incorrect Ratio
🟠 Moderate severity · drivable
Drivable, but fourth gear is slipping, which can cause serious damage if ignored.
What P0734 means
The transmission is slipping in fourth gear — the actual gear ratio doesn't match what the computer commanded.
Symptoms
- Check engine light is on
- Slipping in fourth gear
- Harsh or delayed shifts
- Reduced acceleration at speed
Common causes
- most common: Low or dirty transmission fluid
- common: Worn fourth-gear clutches or bands
- common: Faulty shift solenoid or valve body
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Check and change the transmission fluid and filter | Yes | $100–250 |
| Repair internal transmission slippage | Mechanic | $1500–4000 |
Frequently asked questions
Can I drive with a P0734 code?
Yes, but fourth gear is slipping. Get it checked promptly.
What is the most common cause of P0734?
Low or dirty transmission fluid, or worn fourth-gear clutches.
How much does it cost to fix a P0734?
A fluid change is $100–$250; a rebuild runs $1,500–$4,000.
Related codes
P0730
P0730 Code: Incorrect Gear Ratio
P0733P0733 Code: Gear 3 Incorrect Ratio
P0735P0735 Code: Gear 5 Incorrect Ratio
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.